to the fact that it had shortly before we arrived, taken a bath. The reason for dwelling on this action will appear shortly. In the meantime it was noted that this bird was the only one of the three that showed at the base of its tail what appeared to be either new feathers sprouting and still in their sheaths, or the base of the existing tail- feathers from which the sheath had not yet been removed. After returning from Berkeley about 8:30 o'clock, I went to the glade. The three young thrashers appeared at once and then Brown-eyes, whom I had not seen off of the nest all day, and intensive feeding operations observed were then begun. It was noted that the appearance noted was not so conspicuous as it had been earlier. Close inspection revealed that the bare places were still there, but were partly covered by the tail coverts, which, in these young birds, are light and filmy and are easily displaced by the wing tips temporarily and, when wet remain. June 24th At 7:45 A.M. I went to the glade, all the young appearing at once and very hungry. All of the tails are just alike at the bases, but glimpses of the bare stems at the base of the tail feathers may be seen in all of them, and if one blows on the tail coverts they are easily displaced and the appearance noted yesterday immediately follows. Hence, I assume, that the tail feathers are simply growing fast, and this reminds me that when Brownie's tail was well wet at the base after a heavy rain the shafts of the feathers were quite conspicuous and one could see right through her tail. Since the first observation of today, I was absent until about 4:30, at which time I went to the glade and discovered that I have two young thrashers that are practicing their undersongs or "registering", as I believe it is called. These two were about 5 feet apart, sitting in the Old Man sage, about a foot from the ground. The muscular effort required for so small a volume of sound is surprising and is